1. Osmoregulation and Excretion
Chapter 44
Osmoregulation and Excretion
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

2. An aquatic animal with internal solute concentration of about 500 mOs/l is placed in a fluid of solute concentration of about 700 mOs/l. The animal will osmoregulate in which way?
by passively taking in salts to change its tissue osmolarity to 700 mOs/l
by pumping in salts to keep tissues at 500 mOs/l
by pumping out salts to keep tissues at 500 mOs/l
by pumping out salts to change its tissue osmolarity to 700 mOs/l
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

3. Which combination of osmoregulation mechanisms would you expect to find in a freshwater fish?
salt uptake in gills and salt excretion in urine
salt uptake in gills and water excretion in urine
salt uptake in gills and osmotic water loss in gills
salt excretion in both gills and urine
salt excretion in gills and water excretion in urine
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

4. All except which of the following adaptations are seen in desert animals?
shells, scales, and thick skin
nocturnal activity pattern
conservation of metabolic water
nitrogenous waste excreted as ammonia
production of concentrated urine
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

5. Which of the following occurs as a result of counter-current exchange in the transport epithelium of nasal salt glands in sea birds?
a great volume of fluid can be excreted by salt glands
fluid excreted from salt glands is saltier than seawater
water can be transported back into the bloodstream
fluid excreted from salt glands is about as salty as human tears
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

6. Marine iguanas, found only in the Galápagos Islands, feed on saltwater algae and marine plants. Unlike their land iguana relatives, marine iguanas do which of these?
eliminate abundant dilute urine from their kidney
maintain a blood osmolarity about the same as seawater
have nasal salt glands to excrete salt
have kidneys adapted for water conservation
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

7. Which of these describes urea molecules, the primary nitrogenous waste of mammals?
less toxic than ammonia
more soluble in water than ammonia
produced mainly in cells of the kidney
require less energy to produce than ammonia
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

8. In which of these invertebrate excretory systems do components of body fluids move non-selectively into the tubule?
flatworm protonephridia
earthworm metanephridia
insect Malpighian tubules
none of these
all of these
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

9. Kidney function requires a great deal of ATP
Kidney function requires a great deal of ATP. Transport epithelium in the nephron contains pumps for active transport of all of the following substances except
urea.
sodium ions Na+.
potassium ions K+.
bicarbonate ions HCO3-.
hydrogen ions H+.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

10. Which of the following is part of the two-solute model explaining urine production in the nephron?
NaCl moves out of the nephron into interstitial fluid in the descending loop of Henle.
Fluid entering the distal convoluted tubule is more concentrated than fluid entering the proximal convoluted tubule.
Transport epithelium in the ascending loop of Henle is impermeable to water.
All transport of urea is in the direction of interstitial fluid into tubule fluid.
The ratio of NaCl to urea in interstitial fluid is about the same all along the length of the nephron.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

11. Which one of the following short-term physiological phenomena (not structural adaptations) tends to lead to a decrease in the volume of urine produced?
increase in blood pressure
increase in filtration rate into the Bowman’s capsule
increase in density of aquaporin channels in collecting duct
decrease in blood osmolarity
decrease in sodium ion reabsorption in collecting duct
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.